Method of and apparatus for controlling air flow through tufting needles



April 11, 1967 J. T. SHORT METHOD OF AND APPARATUS FOR CONTROLLING AIR FLOW THROUGH TUFTING NEEDLES 2 Sheets-Sheet 1 Filed April 30, 1963 INVENTOR J06 7: 6%0723 Gm Mm 23%;; firm ATTO NEY A ril} 11, 1967 J. T. SHORT 3,313,26@

METHOD OF AND APPARATUS FOR CONTROLLING AIR FLOW THROUGH TUFTING NEEDLES Filed April 50, 1963 2 Sheets-Sheet 2 a 2 a I COMPRESSED m2 COMPRESSED A/R /Z6 76 g INVENTOR we r Shari BY Wfim,

. A ORNEYS United States Patent METHDD OF AND APPARATUS FOR CONTROL- LING AIR FLOW THRGUGH TUFTTNG NEEDLES Joe T. Short, West Point, Ga, assignor, by mesne assignments, to Callaway Mills Company, La Grange, Ga,

a corporation of Georgia Filed Apr. 30, 1963, Ser. No. 276,906 13 Claims. (Cl. 112266) This invention relates to the making of pile fabric, and more particularly, to a multiple needle tufting machine and method of producing wide yardage goods such as floor covering materials.

Multiple needle tufting machines have been in general use for a number of years. In a typical commercial installation of the type used prior to the present invention, the formation of pile loops or tufts is accomplised through the interaction of needle and looper elements disposed on opposite sides of a backing. Both the needles and the loopers are arranged in long rows extending transversely of the backing and the backing is advanced longitudinally. Each of the needles has an eye near its free end through which a pile yarn is threaded. All of the needles move together toward and away from the backing. As a needle moves towards the backing, it carries with it a pile yarn and projects or inserts a loop of this pile yarn through the backing, and then the looper element moves into the pile loop to hold the loop as the needle is withdrawn from the backing.

With this type of equipment the maximum loop height that can be produced is determined by the position of the looper elements relative to the backing. However, shorter loops may be formed by various back-drawing techniques in which yarn is withdrawn from loops that have been released by the looper elements. Such techniques had been used extensively in the production of floor covering materials having high-low pattern effects.

In the operation of such equipment, the pile yarns frequently are subjected to severe stresses that adversely affect the quality of the products produced and that tend to slow down production operations. Moreover the equipment itself is somewhat delicate, requiring close adjustments and frequent repairs.

A new type of tufting machine designed to overcome many of the disadvantages experienced in connection with the old type of commercial machine is disclosed in my co-pending application, Ser. No. 192,242, filed on May 3, 1962, now Patent No. 3,089,442. The tufting needles of this new machine are hollow and there are no looper elements at all. The pile yarns extend through passages in the needles, and as the needles reciprocate to penetrate the backing, the pile yarns are brought into position with respect to the backing by the gentle action of fluid streams moving through and out of the needles. In the normal operation of the equipment, the movements of the pile yarns relative to the backing are not related directly to the movements of the needles with respect to the backing. For example, the height of a loop formed on the lower face of the backing may exceed substantially the depth of penetration of the needle through the backing, and a pile yarn may be fed downwardly by the fluid stream to fill out a loop even While the needle through which the yarn is threaded moves upwardly out of the backing.

One significant problem in the development of practical tufting systems operating on the fluid flow principle has been the eflicient handling of the fluid. Wide multiple needle machines of the type required for the production of yardage goods include hundreds of tufting needles, each of which must be supplied with fluid under suflicient pressure to achieve the desired yarn feeding action. At high tufting speeds, as for example in the range of 1000 cycles per minute, the volume of fluid required is "ice quite large. Wasteful fluid handling practices detract si nificantly from the overall efficiency and economy of the operation.

It is a general object of the present invention to minimize the volume of fluid utilized in the new fluid flow tufting operations. In particular, the invention envisions a fluid flow pattern in which variations in flow occur during each tufting cycle and in which the flow is correlated with the movements of the tufting needles in such a way as to assure effective yarn feeding during the actual loop forming portions of the tufting cycle while minimizing consumption of fluid during other portions of the cycle.

Another object is to provide improved flow tufting methods and apparatus in which effective control over back stitch formation is facilitated.

Yet another object of the invention is to provide a system in which the rate of feed of pile yarn to the tufting needles of a multiple needle machine is correlated with the rate of yarn utilization at the tuftirn station. The rate of yarn utilization at the tufting station is not uniform throughout a cycle of needle movement in either a conventional or a fluid flow tufting operation. The present invention takes this factor into account and provides for corresponding variations in the rate of delivery of yarn from the yarn supply toward the tufting station.

In one embodiment of the invention, air is employed for impelling the pile yarns through hollow needles that are reciprocated so as to penetrate a backing at intervals. The velocity of the air flowing through the tufting needles determines the pulling forces exerted upon the pile yarns, and hence the effectiveness of the yarn feeding action. Since pile loop formation takes place during only a portion of each machine cycle, it is possible to reduce the air velocity during other portions of the cycle when the yarn feeding requirements are less exacting. This serves to reduce significantly the volume of air handled in the system.

In a typical multiple needle tufting machine embodying the principles of the invention, all of the needles are mounted on a needle carrier extending across the backing. The needle carrier is hollow, providing an air chamber through which each of the hollow tufting needles extends. Inclined openings in the walls of the needles permit air to flow from the hollow chamber of the needle carrier into the yarn passages in the needles in the form of jets directed toward the backing. The supply of air to the needle chamber is interrupted during a portion of each machine cycle so that the air pressure within the chamber will rise and fall cyclically. The maximum yarn feeding forces are developed when these forces may be used effectively, and during other portions of the machine cycle, the flow rate is permitted to drop off so as to minimize waste.

An additional advantage attributable to the varying air flow pattern is that the tendency to form a loose back stitch is minimized. When the needles have moved to positions such that no additional yarn moves into the pile loops, the feeding forces applied to the yarns drop to reduce the likelihood that excess yarn will be fed into the back stitches.

The feeding of pile yarn from a yarn supply toward the needles of the tufting machine also is controlled and timed in such a way as to deliver yarn at a rate which varies over the machine cycle. In a preferred form of the invention, a system of eliptical gears is employed in a drive train extending from the crank shaft of the tufting machine to the drive shaft of the yarn feeding means. The rate of yarn feed is slow at one point in the machine cycle and fast at another point, so that undesirable accumulations of yarn in the zone between the yarn feed means and the tufting station may be avoided effectively.

A more complete understanding of the invention will be gained from a consideration of the following detailed description of certain embodiments illustrated in the accompanying drawings, in which:

FIGURE 1 is a diagrammatic view of a system embodying the principles of the invention, showing schematieally a tufting machine and associated equipment in vertical cross-section;

FIGURE 2 is an enlarged vertical cross-sectional view of a needle carrier and associated components for controlling air flow to the tufting needles in accordance with another embodiment of the invention; and

FIGURE 3 is a diagrammatic view illustrating still another .form of flow controlling means that may be used in the system of the present invention.

The frame of the tufting machine shown in FIGURE 1 includes a base portion 2 and an upper housing unit 4 extending from one side of the machine to the other. Uprights 6 located at the ends of the machine support the upper housing unit 4 in spaced relation to the base portion 2 of the frame, and suitable fabric feeding and guiding means including rollers 8 and 10 advance a backing 12 across the base portion 2 in the zone between the uprights 6 in a conventional manner.

As the backing 12 is advanced, it moves through a tufting zone where pile loops 14 are inserted therethrough. In this zone, the backing 12 is supported from below by a plurality of tine elements or fingers 16 secured to the base portion 2 of the machine and it is held against substantial upward movement by a presser member 18 carried by bracket means 28 secured to the upper housing 4. The presser member 18 is provided with openings 22 in vertical alignment with the spaces between adjacent ones of the tines 16 and also in vertical alignment with the needles 24 of the machine.

These needles 24 are hollow and are mounted on a needle carrier 26 which is moved down and up cyclically to insert the free lower end portions of the needles 24 into the backing 12 and to withdraw the needles 24 from the backing 12. In the illustrated embodiment, the motion of the needle carrier '26 is simple reciprocating motion. With this type of needle motion, it is preferred that the advance of the backing 12 be intermittent so that the backing 12 need not move during the portion of the machine cycle when the lower end portions of the needles 24 are inserted into the backing.

The drive for the needle carrier 26 may include an eccentric 28 rotatable with a driven crank shaft 30 within a bearing member 32. The bearing member 32 is pivotally connected at '34 to the upper end of a push rod 36 mounted for vertical sliding movement in a bearing member 38 carried by the upper housing unit 4 of the machine. The lower end of the push rod 36 is connected rigidly to the needle carrier 26 so that the needle carrier 26 will move up and down as the eccentric 28 rotates about the axis of the driven shaft 30.

Pile yarns 40 for forming the loops 14 may be supplied from any suitable yarn supply or source, such as a creel, not illustrated. In this description, the term yarn is used in a generic sense to refer to any of the various filamentary bodies, or groups or assemblies of such bodies, that may be employed in the formation of tufted products.

The movements of the pile yarns 40 from the yarn supply toward the needles 24 are controlled so as to make available to the needles predetermined lengths of yarn sufiicient for the formation of stitches containing pile loops of the desired heights. A yarn feed mechanism 42 of the notched bar type has been chosen for illustration in FIGURE 1, but it will be understood that other types of mechanisms may "be employed, if desired. The illustrated mechanism includes intermeshing pattern bars 44 and 46 mounted on endless carriers 48 and 50 that are guided through a yarn feeding zone by suitable means 52 and 54 and that are driven in timed relation to the operations of the tufting machine. The illustrated drive for the carriers 48 and 50 includes a drive sprocket 56 carried by a driven shaft 58. The intermeshing pattern bars 44 and 46 cause the yarns 40 to assume undulating paths as they pass through the feeding zone. The individual pattern bars have notches of varying depths in their edges, so that the lengths of yarn stored in a row of these undulations may be different. When the endless carriers 48 and 59 move a pair of pattern bars 44 and 46 out of the zone of intermeshing, different amounts of yarn may be released to different needles 24 in a manner well understood in the art. In instances where level pile fabrics are desired, the notches in the pattern bars may be of uniform depth or the notches may be omitted entirely.

The endless carriers 48 and 50 are advanced during each cycle of the tufting machine a distance equal to the spacing between adjacent ones of the pattern bars. The rate of yarn delivery from a notched bar feed mechanism driven at a uniform rate varies somewhat within each cycle because of the manner in which the bars move out of contact with the yarns. The amount of variation in yarn delivery ratedepends, of course, upon the details and character of the machine setup. For any given machine setup, the actual rate of yarn delivery during various portions of the machine cycle can be established by running an inelastic cord or strand through the notched bar mechanism, turning the drive successively through small angles corresponding to portions of the cycle, and actually marking the inelastic cord to record the amount of yarn delivered during each increment of the cycle. As explained above, one of the objects of the present invention is to correlate the rate of yarn feed from the yarn supply with the rate of consumption at the tufting station. Hence, when a notched bar feed mechanism is employed, it is necessary to take into account the irregularities in yarn delivery rate that are inherent in this type of mechanism.

As indicated in FIGURE 1, the yarn feed mechanism 42 is driven at a variable rate by means of a drive train that includes a pair of intermeshing eliptical gears 60 and 62. The gear 60 is mounted on a shaft 64 driven from the crank shaft 30 of the tufting machine, and the gear 62 is mounted on a shaft 66 that is coupled to the drive shaft 58 of the feed mechanism 42. Hence, the gear 60 has a constant angular velocity, while the gear 62 has a variable angular velocity. In one embodiment, the angular velocity change produced by the gearing is about 2.6 to 1, that is, the maximum angular velocity of the shaft 66 is about 2.6 times its minimum angular velocity. It will be understood, of course, that other ratios are possible. ,The timing is set so that the bulk of the pile yarn 40 delivered by the feed mechanism 42 during each cycle of the tufting machine will be made available during that portion of the cycle when pile loops are being formed. During the portion of the cycle when the back stitch is being formed, much less yarn is fed by the feed mechanism. For example, during the rotation of the crank shaft 30 through an angle of centered about the position at which the needles are at their lowermost points, the length of yarn delivered by the feed mechanism 42 may be three or more times as great as the length of yarn delivered during the rotation of the crank shaft 30 through an angle of 80 centered about the position at which the needles are at their uppermost points.

The variable rate yarn feed may be applied also to tufting machines of conventional construction to correlate the rate of release of yarn with the rate of yarn utilization at the tufting zone. Such machines vary somewhat in constructional details that affect the timing relationships, as for example, by the presence or absence of yarn jerkers at the tufting stations, but persons skilled in the art will have no difficulty in applying the principles of the invention to particular machines.

Attention now will be directed to the fluid supply for the needles 24 of the tufting machine. The relationship between the needles 24 and the needle carrier 26 shown in FIGURE 1 is the same as that between the needles 24a and the needle carrier 26a shown in FIGURE 2. Referring particularly to FIGURE 2, it will be observed that the needle carrier 26a is made up of a housing 68 and a removable end wall 70 so arranged as to provide a fluid chamber 72 which may extend throughout the length of the needle carrier. The individual needles 24a extend vertically through the housing 68 and are held in place by suitable means such as set screws 74. O-rings 76, or other sealing means, are provided in the zones where the needles pass through the walls of the housing 68 so as to prevent leakage of fluid.

The individual nedles 24a have yarn passages 78 extending vertically therethrough. Fluid is admitted to the yarn passages 78 through downwardly inclined openings 80 in the portions of the needles that are disposed within the fluid chamber 72 formed by the needle carrier. As the fluid streams move downwardly through the passages 78 in the needles, they tend to move the pile yarns 40 with them, impelling from the outlet openings of the needles whatever lengths of yarn are made available by the yarn feed means 42.

In the embodiment illustrated in FIGURE 1, compressed air is supplied to the interior of the needle carrier 26 intermittently through valve means 82 and flexible conduits 84. Only one of the conduits 84 is illustrated in FIGURE 1, but it will be understood that similar conduits are located along the lengths of the tufting machine so as to furnish air to the needle carrier 26 at points spaced closely enough to assure reasonably uniform pressure distribution within the air chamber in the needle carrier 26. It is preferred that there be one valve unit 82 for each of the conduits 84.

The valve unit 82 includes a housing 86 shaped to provide upper and lower chambers 88 and 90 connected respectively to air inlet and outlet conduits. The movement of air from the chamber 88 to the chamber 90 is controlled by a valve element 92 that is normally biased to a closed position by a spring 94 but which may be moved to an open position by a cam element 96 mounted on a cam shaft 98. Valve units of this type are well known, and the showing contained in FIGURE 1 is intended as schematic only. Persons skilled in the art will have no difiiculty in selecting a commercially available valve unit suitable for operation in the manner contemplated by the present invention.

The cam shaft 98 of the valve unit 82 is driven from the crank shaft 30 of the tufting machine. It rotates once during each cycle of movement of the needle bar 26. By selecting a cam element 96 of suitable shape, air may be permitted to flow from the chamber 88 to the chamber 90 during any desired portion of the tufting cycle.

An example of the valve timing and pressure conditions for one practical machine setup will serve to clarify further the principles of the invention. A yardage machine of inch gauge (center to center spacing of longitudinal rows of pile loops) was employed to tuft 3700 denier texturized continuous filament nylon pile yarns into a woven jute backing at the rate of 1000 stitches per minute. In this installation all of the needles were hollow and were supplied with air from a chamber in the needle carrier, as indicated in FIGURE 1. The valves for controlling the admission of air to the needle carrier were supplied continuously with air under a pressure of about 20.5 pounds per square inch gauge and were operated from the crank shaft of the machine. Considering the position of the crank shaft when the needles are farthest from the backing as the starting point of a cycle, the valves opened at about the 140 point in the cycle and closed again at about the 330 point in the cycle. The maximum air pressure in the needle carrier chamber, reached at a moment just prior to the closing of the valves, was about pounds per square inch gauge. After the closing of the valves, the air continued to flow through the tufting needles and the pressure within the chamber fell 05 gradually, reaching a minimum value of about 12.7 pounds per square inch gauge just prior to the opening of the valves during the next cycle. Under these conditions, the tufting operation proceeded smoothly and a satisfactory tufted product was produced.

A somewhat ditferent form of flow controller is illustrated in FIGURE 2 of the drawings. In this embodiment, the push rods 36:: on which the needle carrier 26a is mounted are hollow at their lower end portions and air is directed to the needle carrier through these push rods. The needle carrier 260 has a plurality of openings 100 spaced along its top wall, and the push rods 36a are aligned with these openings, so that when the push rods are connected to the needle carrier, as by bolts 102, the interior passages 104 in the push rods will be in communication with the chamber 72 of the needle carrier 26a through the openings 100.

At the location of each of the push rods 36a, the upper housing unit 4 of the machine frame has attached thereto,

as by bolt means 106, a valve body 108. An annular air chamber is located on the interior of the valve body 108, and a suitable fitting 112 serves to couple the air chamber 110 with a conduit 114 for continuously supplying air at a predetermined pressure. A hearing sleeve 1% extends axially into the lower end portion of the valve body 108 in surrounding relation to the push rod 36a.

Near the upper end of the bore 104 the push rod 36a is provided with ports 118 that may communicate with the annular air chamber 110 in the valve body 108 through openings 120 in the bearing sleeve 116. FIGURE 2 illustrates the parts in the positions they occupy when the needles are at or near their lowermost points. As the needle carrier 213a moves upwardly, the ports 118 will shift relative to the openings 120 in the bearing sleeve 116 to close off the flow of air from the chamber 110 to the bores 104 of the push rods 36a.

It is desirable that means be provided for permitting adjustment of the timing of the air flow cycle. In FIG- URE 2, the bearing sleeve 116 is illustrated as being threadedly connected, at 122, to the valve body 103. Rotary movement of the bearing sleeve 116 will serve to shift the positions of the openings 120 vertically with respect to the ports 118 in the push rod 36a. When the desired position has been reached, the sleeve 116 may be locked in place by a set screw 124. In order to assure proper circumferential alignment of the ports 1-18 and the openings 120, a notch is provided in position to cooperate with the set screw 124 so that the angular position of the sleeve 116 before and after adjustment will be the same.

It will be understood also that suitable seals 126 and gaskets 128 should be employed in the embodiment of FIGURE 2 to prevent undesired leakage between the several parts that go to make up the air flow channel.

The embodiment illustrated in FIGURE 3 is similar in many respects to the embodiment illustrated in FIGURE 1. The conduit 84a may be identical to the flexible conduit 84, for example. The flow of air into the conduit 84a is controlled by a conventional solenoid valve 130 actuated in timed relation to the operation of the tufting needles. The solenoid for the valve 130 is actuated intermittently through a switch 132, one member of which is attached to a cam follower 134 that rides on a cam 136. The cam 136 is fixed on a driven shaft 138 that is coupled to the crank shaft of the tufting machine in such a manner that the shaft 138 makes one revolution for each revolution of the crank shaft 30. The cam 136 illustrated dia grammatically in FIGURE 3 is of such a shape as to hold the switch 132 closed for about two-thirds of each machine cycle. This specific relationship is not essential. The period of time during which the valve 130 is held open and the timing of the valve operations with respect to the movements of the tufting needles should be established in the light of the particular machine setup under consideration.

Various other changes and modifications will suggest themselves to persons skilled in the art. It is intended therefore that the foregoing description be considered as exemplary only, and that the scope of the invention be ascertained from the following claims:

I claim:

1. A multiple needle tufting machine comprising means for advancing a backing along a path, a needle carrier extending across said path and having an air chamber therein, a plurality of hollow needles mounted on and extending through said needle carrier and each having a free end portion projecting toward the backing, each of said needles having a longitudinally extending passageway therein terminating in an outlet opening in said free end portion of the needle and having a yarn inlet opening at the end thereof opposite said outlet opening, means for moving said needle carrier cyclically back and forth to insert the free ends of said needles through the backing far enough to expose said outlet openings on the opposite side of the backing and then to withdraw said needles from the backing, means for supplying air under pressure to said chamber during only a portion of each cycle of movement of said needle carrier beginning when the needle carrier nears its point of closest approach to said backing and ending when the needle carrier nears the point where it is farthest from said backing, and means for positively feeding along paths leading to the yarn inlet openings of said needles during each cycle of movement of said needle carrier controlled lengths of yarn sufiicient for the formation of stitches containing permanent pile loops, each of said needles having at least one inclined orifice therein communicating at one end with said passageway in the needle and at the opposite end with said air chamber for directing a jet of air along said passageway toward said outlet opening in said needle to impel yarn relative to said backing out of said outlet opening and away from said needle selectively beyond the depth of penetration of said needles through said backing.

2. A multiple needle tufting machine comprising means for advancing a backing along a path, a needle carrier extending across said path and having an air chamber therein, a plurality of hollow needles mounted on and extending through said needle carrier and each having a free end portion projecting toward the backing, each of said needles having a longitudinally extending passageway therein terminating in an outlet opening in said free end portion of the needle and having a yarn inlet opening at the end thereof opposite said outlet opening, a plurality of supports connected to said needle carrier and having air passages therein communicating with said chamber, each of said supports being mounted for reciprocating movement within a member having an air space therein, means for reciprocating said supports toward and away from said backing to insert the free ends of said needles through the backing far enough to expose said outlet openings on the opposite side of the backing and then to withdraw said needles from the backing, means for supplying air under pressure continuously to said air space, each of said supports having port means therein communicating with said air space during a portion of each stroke of said supports to permit air to flow into said chamber, and means for positively feeding along paths leading to the yarn inlet openings of said needles during each cycle of movement of said needle carrier controlled lengths of yarn sufficient for the formation of stitches containing permanent pile loops, each of said needles having at least one inclined orifice therein communicating at one end with said passageway in the needle and at the opposite end with said air chamber for directing a jet of air along said passageway toward said outlet opening in said needle to impel yarn relative to said backing out of said outlet opening and away from said needle.

3. A multiple needle tufting machine comprising means for advancing a backing along a path, a needle carrier extending across said path and having an air chamber therein, a plurality of hollow needles mounted on and extending through said needle carrier and each having a free end portion projecting toward the backing, each of said needles having a longitudinally extending passageway therein terminating in an outlet opening in said free end portion of the needle and having a yarn inlet opening at the end thereof opposite said outlet opening, a plurality of supports connected to said needle carrier and having air passages therein communicating with said chamber, each of said supports being mounted for reciprocating movement within a member having an air space therein, means for reciprocating said supports toward and away from said backing to insert the free ends of said needles through the backing far enough to expose said outlet openings on the opposite side of the backing and then to withdraw said needles from the backing, means for supplying air under pressure continuously to said air space, each of said supports having port means therein communicating with said air space during a portion of each stroke of said supports to permit air to How into said chamber, adjustable means for controlling the portion of the stroke of each of said supports during which said port means are in communication with said air space, and means for positively feeding along paths leading to the yarn inlet openings of said needles during each cycle of movement of said needle carrier controlled lengths of yarn sufficient for the formation of stitches containing permanent pile loops, each of said needles having at least one inclined orifice therein communicating at one end with said passageway in the needle and at the opposite end with said air chamber for directing a jet of air along said passageway toward said outlet opening in said needle to impel yarn relative to said backing out of said outlet opening and away from said needle.

4. A multiple needle tufting machine comprising means for advancing a backing along a path, a needle carrier extending across said path and having an air chamber therein, a plurality of hollow needles mounted on and extending through said needle carrier and each having a free end portion projecting toward the backing, eachof said needles having a longitudinally extending passageway therein terminating in an outlet opening in said free end portion of the needle and having a yarn inlet opening at the end thereof opposite said outlet opening, means for moving said needle carrier cyclically back and forth to insert the free ends of said needles through the backing far enough to expose said outlet openings on the opposite side of the backing and then to withdraw said needles from the backing, means for supplying air under pressure to said chamber during only a portion of each cycle of movement of said needle carrier beginning when the needle carrier nears its point of closest approach to said backing and ending when the needle carrier nears the point where it is farthest from said backing, means for positively feeding along paths leading to the yarn inlet openings of said needles during each cycle of movement of said needle carrier controlled lengths of yarn sufficient for the formation of stitches containing permanent pile loops, and means for driving the last-mentioned means at a varying rate such that a major portion of the yarn fed during a cycle is fed during said portion of the cycle, each of said needles having at least one inclined orifice therein communicating at one end with said passageway in the needle and at the opposite end with said air chamber for directing a jet of air along said passageway toward said outlet opening in said needle to impel yarn relative to said backing out of said outlet opening and away from said needle and to a distance beyond the penetration of said needles through said back- 5. In a multiple needle tufting machine having a plurality of tufting needles, a needle drive means for moving said needles cyclically toward and away from a backing and a yarn feeding mechanism of the type which includes a pair of endless carriers having intermeshing pattern bars thereon for supporting a plurality of yarns in undulating paths, the improvement which comprises a yarn feeding mechanism drive means responsive to the motion of said needle drive means for advancing said endless carriers at a variable rate which rises to a maximum and falls to a minimum during each cycle of movement of said tufting needles.

6. In a multiple needle tufting machine having a plurality of tufting needles, power driven means for moving said needles cyclically toward and away from a backing and a yarn feeding mechanism of the type which includes a pair of endless carriers having intermeshing pattern bars thereon for supporting a plurality of yarns in undulating paths, the improvement which comprises a drive train connecting said carriers to said power driven means and including a pair of intermeshing noncircular elliptical gears for advancing said endless carriers at a variable rate.

7. A method of making a tufted fabric having pile loops extending from a backing comprising a cycle including the steps of advancing the backing longitudinally; inserting and withdrawing from the backing the tip portions of a plurality of hollow needles each carrying a pile yarn extending from the backing through the hollow passage in the needle and back to a yarn supply; feeding from the yarn supply a controlled length of yarn for each needle; and flowing gas continuously through said passages in said needles in the direction of the tip portions thereof in such a manner that the flow rate decreases during a portion of the time when the relative movement of the needles and the backing is in a direction to insert the needles through the backing and increases, during a portion of the time when the needles extend through said backing, beyond a velocity sufficient to impel yarns relative to said backing through said needles and maintains a velocity suflicient to continue to impel yarns relative to said backing through said needles until the tip portions of the needles are Withdrawn from the backing.

8. A method of making a tufted fabric having pile loops extending from a backing comprising a cycle including the steps of advancing the backing longitudinally; inserting and withdrawing from the backing the tip portions of a plurality of hollow needles each carrying a pile yarn extending from the backing through the hollow passage in the needle and back to a yarn supply; feeding from the yarn supply a controlled length of yarn for each needle at a varying rate such that the major portion of the yarn fed during the cycle is delivered during a minor portion of the cycle which includes the moment of maximum penetration of said backing by said needle; and flowing gas continuously through said passages in said needles in the direction of the tip portions thereof in such a manner that the flow rate decreases during a portion of the time when the relative movement of the needles and the backing is in a direction to insert the needles through the backing and increases, during a portion of the time when the needles extend through said backing, beyond a velocity suflicient to impel said yarns relative to said backing through said needles and maintains a velocity suflicient to continue to impel the yarns relative to said backing through said needles until the tip portions of said needles are withdrawn from said backing.

9. A method of making a tufted fabric having pile loops extending from a backing comprising a cycle including the steps of advancing the backing longitudinally; inserting and withdrawing from the backing the tip portions of a plurality of hollow needles each carrying a pile yarn extending from the backing through the hollow passage in the needles and back to a yarn supply; feeding from the yarn supply a controlled length of yarn for each needle; and flowing gas continuously through said passages in said needles in the direction of the tip portions thereof while varying the flow rate within each cycle to provide a maximum flow rate beyond a velocity sufiicient to impel said yarns relative to said backing through said needles during the portion of the cycle when the tip portions of said needles are withdrawn from the backing.

10. A multiple needle tufting machine comprising means for advancing a backing along a path, a plurality of hollow tufting needles mounted on one side of said path and being arranged in a group extending across said path, each of said needles having a yarn passage therein terminating in an outlet opening in the end portion thereof closest to said backing, drive means for relatively moving said group of needles and said backing to insert said end portions of the needles through the backing and withdraw them from the backing, means for moving from a yarn supply during each cycle of relative movement of said needles and said backing a controlled length of yarn for each of said needles, means forming a chamber for compressed gas, means for admitting gas from said chamber continuously to said yarn passages in said needles to cause said gas to flow through said passages in streams directed toward said outlet openings, said last mentioned means comprising valve means being operatively connected to said drive means for maintaining said valve means open during the portion of the cycle during which the needles approach the bottom dead center position of the cycle and until the needles are withdrawn from the fabric, and for maintaining the valve closed during the remainder of the cycle.

11. A multiple needle tufting machine comprising: means for advancing a backing along a path, a needle carrier extending across said path and having a fluid chamber therein, a plurality of hollow needles mounted on and extending through said needle carrier and each having a free end portion projecting toward the backing, each of said needles having a passage therein terminating in an outlet opening in said free end portion of the needle and having a yarn inlet opening spaced from said outlet opening for receiving a yarn leading from a yarn supply, means for relatively moving said needle carrier and said backing cyclically toward and away from each other to insert the free end portions of said needles through the backing far enough to expose their outlet openings on the opposite side of the backing and then to withdraw said needles from the backing, means for controlling the movements of the yarns from the yarn supply toward the yarn inlet openings in said needles to make available to the yarn inlet openings of said needles controlled lengths of yarn sufficient for the formation of stitches containing pile loops, and means for delivering fluid to said chamber, the lastmentioned means including valve means operating in timed relation to the relative movement between said needle carrier and the backing to interrupt the flow of fluid to said chamber during the portion of each cycle while the needles are entering the backing, each of said needles having at least one inclined orifice therein communicating at one end with said passage in the needle and at the opposite end with said chamber for directing fluid along said passage toward said outlet opening in said needle, said means for delivering fluid to said chamber and said at least one inclined orifice being constructed and arranged to deliver fluid through said needle at a velocity suflicient to impel said yarn through said needle until said outlet opening is withdrawn from said backing, to impel yarn relative to said backing out of said outlet opening and away from said needle selectively beyond the needle penetration through said backing.

12. In a method of tufting wherein hollow needles carrying yarn therein are cyclically inserted through a backing for forming successive loops of yarns in said backing, the steps of continuously supplying fluid to said needles under suflicient pressure for expelling the yarns relative to said backing from said needles, and modulating the feeding of said fluid to said needles in timed relationship to the cycles of insertion of said needles through said backing to increase the fluid fiow through said needles after the needles penetrate the backing and until the needles are withdrawn from the backing at which time the fluid flow is decreased.

13. In a tufting machine of the class wherein a backing is fed along a predetermined path through the tufting machine and hollow needles are adapted to insert yarns supplied thereto cyclically through the backing for the formation of loops of yarn on at least one side of the backing, means for supplying air to said needles at a velocity sufiicient to expel said yarns relative to said backing from said needles, said cycle including a portion when the tip portions of the needles are positioned on one side of said path and a portion when the tip portions of the needles are positioned on the other side of said path, means for regulating the flow of air to said needles in timed relationship to the cyclic insertion of yarn through the backing, means for increasing the rate of air supply when the tip portions of the needles are positioned on said one side of said path and until the needles are on the other side of said path and for then decreasing the rate of air supply when the tip portions 12 of the needles are on said other side of said path, and means for regulating the supply of yarns to said needles in timed relationship to the cyclic insertion of yarn through said backing.

References Cited by the Examiner UNITED STATES PATENTS 984,195 2/1911 Cooper 11279 1,830,463 11/1931 Foster et al. 11279 1,997,869 4/ 1935 Loos 11279 2,422,126 6/ 1947 Parker 112-80 2,866,424 12/1958 Masland 11279.6 2,932,339 4/1960 Odenweller 11279 X 3,039,170 6/1962 Marshall 11279 3,089,442 5/ 1963 Short 11279 3,225,723 12/1965 Wilkes 112-80 FOREIGN PATENTS 21,839 1911 Great Britain. 618,165 2/ 1949 Great Britain.

JORDAN FRANKLIN, Primary Examiner.

M. I. COLITZ, I. R. BOLER, Assistant Examiners. 

7. A METHOD OF MAKING A TUFTED FABRIC HAVING PILE LOOPS EXTENDING FROM A BACKING COMPRISING A CYCLE INCLUDING THE STEPS OF ADVANCING THE BACKING LONGITUDINALLY; INSERTING AND WITHDRAWING FROM THE BACKING THE TIP PORTIONS OF A PLURALITY OF HOLLOW NEEDLES EACH CARRYING A PILE YARN EXTENDING FROM THE BACKING THROUGH THE HOLLOW PASSAGE IN THE NEEDLE AND BACK TO A YARN SUPPLY; FEEDING FROM THE YARN SUPPLY A CONTROLLED LENGTH OF YARN FOR EACH NEEDLE; AND FLOWING GAS CONTINUOUSLY THROUGH SAID PASSAGES IN SAID NEEDLES IN THE DIRECTION OF THE TIP PORTIONS THEREOF IN SUCH A MANNER THAT THE FLOW RATE DECREASES DURING A PORTION OF THE TIME WHEN THE RELATIVE MOVEMENT OF THE NEEDLES AND THE BACKING IS IN A DIRECTION TO INSERT THE NEEDLES THROUGH THE BACKING AND INCREASES, DURING 